Total Knee Replacement (TKR)

Total knee replacement, also called total knee arthroplasty, is a surgical procedure in which the worn out or damaged surfaces of the knee joint are removed and replaced with artificial parts. The knee is made up of the femur (thigh bone), the tibia (shin bone), and patella (kneecap). The meniscus, the soft cartilage between the femur and tibia, serves as a cushion and helps absorb shock during motion. Arthritis (inflammation of the joints), injury, or other diseases of the joint can damage this protective layer of cartilage, causing extreme pain and difficulty in performing daily activities. Your doctor may recommend surgery if non-surgical treatment options have failed to relieve the symptoms.

Indications

Total knee replacement surgery is commonly indicated for severe osteoarthritis of the knee. Osteoarthritis is the most common form of knee arthritis in which the joint cartilage gradually wears away. It often affects older people.

In a normal joint, articular cartilage allows for smooth movement within the joint, whereas in an arthritic knee the cartilage itself becomes thinner or completely absent. In addition, the bones become thicker around the edges of the joint and may form bony “spurs”. These factors can cause pain and restricted range of motion in the joint.

Your doctor may advise total knee replacement if you have:

Severe knee pain which limits your daily activities (such as walking, getting up from a chair or climbing stairs).

Moderate to severe pain that occurs during rest or awakens you at night.

Chronic knee inflammation and swelling that is not relieved with rest or medications

Causes

The exact cause of osteoarthritis is not known, however there are several factors that are commonly associated with the onset of arthritis and may include:

Injury or trauma to the joint

Fractures at the knee joint

A family history of knee arthritis

Increased body weight

Repetitive overuse

Joint infection

Inflammation of the joint such as rheumatoid arthritis

Connective tissue disorders

Diagnosis

Your doctor will diagnose osteoarthritis based on the medical history, physical examination, and X-rays.

X-rays typically show a narrowing of the joint space in the arthritic knee.

Procedure

The goal of total knee replacement surgery is to relieve pain and restore the alignment and function of your knee.

The surgery is performed under spinal or general anaesthesia. Your surgeon will make an incision in the skin over the affected knee to expose the knee joint. Dr Hocking uses computer navigation to accurately cut the bones. Then the damaged portions of the tibia and femur bone are cut at appropriate angles using specialized jigs. The tibial component is implanted and then the femoral component is implanted to the end of the femur with or without bone cement. The femur and the tibia with the new components are then put together to form the new knee joint. To make sure the patella (knee cap) glides smoothly over the new artificial knee, its rear surface is also prepared to receive a plastic component. With all the new components in place, the knee joint is tested through its range of motion. The entire joint is then irrigated and cleaned with a sterile solution and then the knee is injected with local anaesthetic and a medication which assists control blood loss. The incision is carefully closed and a sterile dressing is placed over the incision.

Post-Operative Care

Rehabilitation begins immediately following the surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement. You will be able to walk with crutches or a walker. Your physical therapist will also provide you with a home exercise program to strengthen thigh and calf muscles.

Risks and Complications

As with any major surgery, possible risks and complications associated with total knee replacement surgery include:

Knee stiffness

Infection

Blood clots (deep vein thrombosis)

Nerve and blood vessel damage

Ligament injuries

Patella (kneecap) dislocation

Plastic liner wears out

Loosening of the implant

If you find difficulty in performing simple activities such as walking or climbing stairs because of your severe arthritic knee pain, then total knee replacement may be an option for you. It is a safe and effective procedure to relieve pain, correct leg deformity, and help you resume your normal activities of daily living